Apparatus for converting hydrocarbon oils



Feb.1 27, 1945. w. J. DEGNl-:N ETAL.

APPARATUS FOR CONVERTING HYDROCARBON OILS Original Filed April 2, 1938WILLIAM J4 DEGNEN HENRY MNELLY J2. PERCIVAL C- KIET INVENTORS ATTOR EYPatented Feb. 27, 1945 APPARATUS Foa coNvER'rING HYDRooARBoN olLsWilliam J. Degnen, Westfield, N. J., Henry M. Nelly, Jr., Houston, Tex.,and Percival C. Keith, Peapack, N. J., assignors to The M. W. KelloggCompany, Jersey City, N. J., a corporation of Delaware Originalapplication April 2, 1938, Serial No. 199,703. Divided and thisapplication December 31, 1941, Serial No. 425,042

3 Claims.

The present application is a divisional of our application, Serial No.199,703, filed April 2, 1938. U. S. Patent 2,290,580, issued July 2l,1942.

Our invention relates to an apparatus for converting hydrocarbon oils,and more particularly to an apparatus adapted for the conversion of highboiling hydrocarbons into low boiling hydrocarbons and similarendothermic catalytic conversions, such as the catalytic reforming oflow anti-knock naphtha into high octane motor fuel.

The catalytic cracking of hydrocarbon oils is known to the art. Ingeneral, the methods of the prior art consist; in heating hydrocarbonoil to cracking temperatures and passing highly heated oil or its vaporsthrough a cracking zone in the presence of a suitable catalyst in orderto convert the hydrocarbon oil into the desired products. For variousreasons, the catalyst becomes less eiiective with use and it isnecessary to reviviiy it. During an operation,.the catalyst varies inelectiveness from maximum to minimum so that, for any given catalystbed, only average effectiveness is obtained.

Cracking is an endothermic reaction, and oil heated to crackingtemperature and passed into a cracking zone will, as the reactionprogresses, cool, and with cooling there is a progressive decrease inthe cracking reaction until no cracking occurs. In our co-pendingapplication, Serial No. 199.702, we have provided means for supplyingheat to the reaction chamber during the cracking reaction in order toincrease the amount of cracking per pass. In the instant application, Wepropose to divide the catalytic bed or reaction chamber into a pluralityof stages yso that the partially cracked material may be heated betweenstages.

One object of our invention is to provide an apparatus adapted for usein cracking in the presence of a catalyst, in which the catalystmaterial is continuously being removed and revivied, in a plurality ofbeds with an intermediate step of heating.

Another object of our invention is to provide an apparatus adapted foruse in cracking in the presence of a catalyst in which the catalytic bedis continuously being removed and revivied so that the catalytic bedwill remain of substantially constant effectiveness. k

A further object of our invention is to provide apparatus capable ofcarrying out a method of catalytic cracking in which the catalyst iscontinuously removed and reviviied.

Another object of our invention-is to provide a catalyst chamber inwhich the catalyst ls continuously replaced.

Other and further objects of our invention will appear from thefollowing description.

In the accompanying drawing, which forms part of the instantspecification, and which is to be read in conjunction therewith:

The gure is a schematic view of apparatus embodying our invention andcapable of carrying out the process of our invention.

In general, our invention contemplates the provision of apparatus inwhich oil vapors to be conl verted are -brought into contact with acatalyst in a rst conversion zone in which the catalyst is continuouslybeing replaced so that the composition of the oil vapor leaving thecatalyst chamber will be substantially constant and may flow to heatingequipment without precautions being taken for change in its composition,and then to a second reaction chamber in which the catalyst is likewisecontinuously being maintained at a constant state of activity, so thatthe cracking vapors may iiow to after equipment without constantlywatching for changes in its composition, and the necessity of varyingthe operation of the after equipment. This is a major advantage over theintermittent processes of the prior art in which the products leavingthe catalyst chamber may vary in composition. In an intermittentprocess, for example, in which hydrocarbon oils are cracked to formgasoline-like hydro.. carbons, at the beginning of a period the vaporsleaving the reaction chamber may contain from 40% to50% of gasoline,while, at the end of the period, they may contain as low as 15% to 20%of gasoline.

In the intermittent processes in order to obtain high cracking per pass,the cracking period must necessarily be short duel to the fact that thecatalyst activity falls olf rapidly. Inf a continuous process, thecracking per pass may be raised by increasing the circulation rate ofthe catalyst per unit of oil charged.

In the intermittent processes, the oil vapors to be converted passthrough the reaction chamber in Contact with catalyst of highestactivity only during one part of a period. After this period has beenpassed the catalyst is progressively decreasing in activity. In ourmethod of continuously circulating a catalyst in contact with the oilvapors, the average composition of the catalyst remains substantiallyconstant and a portion of the oils vapors always contacts some catalystof highest activity.

The catalyst being continuously removed from the reaction chamber iscontinuously revivied by combustion of the carbonaceous deposit thereonand recirculated to the catalyst chamber whereby the catalyst iscontinually circulated in a cyclic operation through the system at anelevated tempcrature.

By splitting the reaction into two stages and supplying heat to thematerial during each of the stages, the drop in temperature -withresultant decrease in cracking is minimized.

More particularly, referring now to the drawing, the oil to be cracked,which may be of any suitable character, such as gas oil or the like, is.pumped through pipe I3 by pump I2, through convection heating coil I infurnace I4, through radiantly heated tubes I6, the oil being withdrawnfrom the furnace through transfer pipe I1 for passage into the separatorI8, into which it is separated into vapors and unvaporized oil. Acontrol reflux may be introduced into the separator I8 through pipe I9.Superheated steam may be delivered into separator I8 through pipe toassist in the separation of the vapors from the heated oil. Theunvaporized oil is withdrawn from the separator I8 through pipe 2| andpumped by pump 22 to heat exchanger 23, which is supplied with a coolingmedium through pipe 24. The cooled unvaporized oil leaves the cooler 23through pipe 25 and may be passed through pipe 26, controlled by valve21, to storage. A portion of the cooled unvaporized oil may be returnedto the separator through pipe 28, controlled by valve 29, from whence itmay be delivered through pipe 30, controlled by valve 3|, into contactwith the highly heated charging stock to control its temperature. Aportion of the unvaporized oil may be recycled for tower bottoms fluxingby opening valve 32. The highly heated oil vapors are withdrawn from theseparator I8 through a pipe 33 and passed through pipe 38 forintroduction into the base of the reaction chamber 39. The crackedvapors are withdrawn from the reaction chamber through pipe 45 and areheated in coil 34 of furnace I4. The reheated partially converted vaporsare withdrawn from the furnace I4 through pipe 60 and pass into the baseof reaction chamber 39'. The converted vapors leave the reaction chamberthrough line 45 and .pass to the usual after treatment, includingdephlegmation and condensation, for recovery of the convertedhydrocarbons.

In the reaction chambers 39 and 39', the heated vapors react to formlighter hydrocarbons in the presence of a catalyst. The catalyst in ourmethod and apparatus is of a nature so that it can be fed to andwithdrawn from reaction chambers continuously. The fresh catalyst, whichmay be used catalytic material which has been reviviiied, is fed througha conveyor duct |08 to a' catalyst distributing bin 6 I. From thecatalyst distributing bin 6| the catalytic material may flow throughconduits 62 and 63 controlled by respective Valves 84 and B5. Theconveyor duct |08 is provided with any suitable conveying means I drivenby a suitable prime mover such as electric motor ||2. Catalytic materialfrom the distributing bin 6| is adapted to flow into a catalytic feedinghopper ||0' through duct 63. Similarly, catalyst material fromdistributing bin 8| may flow through conduit 62 if valve 84 be opened,into catalyst feeding hopper ||0. The feeding of catalyst material I| 3from the hoppers ||0 and ||0' is controlled by respective cone typevalves ||4 and ||4, each provided with hydraulic operating means ||5 andII5'. The cata- 78 lyst. material passes from respective feeding hoppers||0 and ||0 through ducts IIS and IIS' into respective sealing hoppers II1 and I I1'. The catalyst material is fed from the sealing hopper ||1into the reaction chamber 39 by a rotary bucket type valve ||8, operatedby an electric motor I|9 through suitable gears |20. Similarly, catalystmaterial from sealing hopper ||1' is fed to the reaction chamber 39'through a rotary bucket type valve II8' operated by an electric motor Il9 through suitable gears |20'.

The used catalytic material is withdrawn from the reaction chamber 38 byrotary buckettype valve |2| operated by an electric motor |22. In thesame manner, used catalytic material leaves the reaction chamber 39'through a rotary bucket type valve |2I' operated by an electric motor|22. The motors ||9, II9', |22 and |22 maybe synchronized so that therate of feeding and the rate of withdrawal are kept the same. The usedcatalytic material leaving reaction chamber 39 via valve I2I, passesinto a sealing hopper |23, the exhaust of which is controlled by a conetype valve |24, operated by a hydraulic operating mechanism |25. In thesame manner, catalytic material leaving the reaction chamber 39 viavalve |2| passes into a sealing hopper |23', the exhaust of which iscontrolled by a cone type valve |24' operated by a hydraulic operatingmechanism |25.

The hydraulic operating mechanisms II5, I I5', |25 and |25', areSupplied with hydraulic fluid through pipes |26, |26', |21 and |21',respectively. A fluid pump |28 operated by an electric motor |29supplies fluid from a pipe |30 for the functioning of the hydraulicoperating mechanisms, A timing control mechanism |3| of any suitabletype known to the art, controls electric motor |29, so that the conetype valves ||4, II4', |24 and |24', are intermittently operated tointroduce fresh catalytic material into the sealing hoppers I I1 and||1, and to withdraw used catalytic material from the sealing hoppers|23 and |23.

An inert gas, such as flue gas, carbon dioxide, or light hydrocarbongases under suitable pressure and at a suitable temperature, isintroduced into manifold |32. A pipe |33 controlled by a valve |34permits gas from the manifold |32 to flow into the feeding hopper ||0.Likewise, gas from the manifold |32 may pass through pipe 66 into pipe|33' controlled by valve |34' for lntroduction into the feeding hopper||0'. The pressure of the gas is such that it is slightly in excess ofthe pressure existing in the catalyst chambers 39 and 39. The placing ofthe feeding hoppers |I0 and ||0' and the communicating sealing hoppers||1 and II1' under this pressure will effectively prevent leakageoutwardly of cracked vapors. Such leakage as will occur past cone typevalves 4 and II4' will be of the sealing gas into the sealing hoppers||1 and III'. The capacity of the sealing hoppers is sufficientlygreater than the discharge hoppers |35 and |35 that there will always bea quantity of material present in the sealing hoppers ||1 and ||1', thusassuring continuity of feed to the revivifier. The pressure in feedinghoppers ||0 and ||0 may be readily controlled by valves |34 and |34',which may be automatically controlled by suitable differential pressurecontroller known to the art (not shown), placed between the sealinghopper ||0 and the reaction chamber 39, and between sealing hopper H0and reaction chamber 39'. Sealing gas from manifold |82 is alsointroduced through pipe |36 controlled by valve |31, into dischargesealing hopper`I23. By controlling valve |31 the 4pressure within thehopper |23 is controlled to be slightly in excess of that which existsin pipe 38, and in the reaction chamber- 39, so that gas introduced intothe sealing hopper |23 willv denude or strip the catalytic materialdischarged with vapors which are carried, either absorbed in thecatalytic material or physically mixed in the mass. The stripped vaporsand sealing gas will leave the sealing hopper |23 through a pipe 40controlled by a valve 4I, and pass through pipe 38' into the reactionchamber along with the hot vapors to be reacted.

correspondingly, sealing gas from manifold |32 passes through pipe 66through pipe |36. controlled by valve |31' into discharge sealing hopper|23'. By control of valve |31', the pressure within hopper |23' iscontrolled to be slightly in excess of that which exists in pipe 60 andin the reaction chamber 39 so that gas introduced into the sealinghopper |23 will strip the catalytic material of vapors absorbed or mixedtherewith. The stripped vapors and sealing gas will leave the sealinghopper |23 through a pipe 40 controlled by valve 4I' and pass throughpipe 60 into reaction chamber along with the hot vapors to be reacted.

The catalytic reaction chambers 39 and 39' may be operated with thecatalyst feed in parallel or in series. When the operation is inparallel, both valves 64 and 65 are opened so that catalytic materialfromthe catalyst distributing bin 6I will flow through conduits 62 and63 into catalyst feeding hoppers and ||0'. The motor II2 operating theconveyor I I' in the conveying tube |08' is stopped. The valve 10controlling-the duct 1I leading to the conveyor tube is closed. Thevalve 12 controlling the conduit 13 leading to the hopper 14 is opened.Catalytic material discharged into the catalytic material dischargehopper |35 passes through the duct |31 into the conveyor tube 15 forfeeding by conveyor screw 16, which is operated by motor 11, into thehopper 14. Catalytic material from hopper 14 is fed through conveyortube |38 by conveyor I 43 to a catalyst revivifying feeding hopper 205through a duct 204. The catalytic material discharged from catalyticmaterial discharge hopper passes through duct 13 into hopper 14 with theused catalytic material being discharged thereinto by conveyor screw 16.

When the reaction chambers 39 and 39 are operated with the catalyst feedin series, valve 64 is closed while valve 65 is left open. Valve 12controlling duct 13 is closed, while valve 10 controllng duct 1| isopened. The motor I I2' controlling conveyor I I' for operation inconveyor tube |08' is started. Fresh catalytic material from thecatalytic material distributing bin 6| is fed to feeding hopper IIO asbefore. The discharged catalytic materialfrom catalytic discharge hopper|35 is conveyed by conveyor I I I to the catalyst feeding hopper IIO.The used catalytic material is discharged from the catalytic materialdischarge hopper |35 through duct |31, for passage into the conveyortube 15, as before. It will be seen that ln the series operation the owof vapors is countercurrent to the flow of catalytic material. Thecounterow also holds for each chamber in the parallel operation but thecounterfiow is half the length of that which obtains in theseriesoperation. In both operations there is a withdrawal of the vaporsfrom the first reaction chamber with reheating before passage into thesecond reaction chamber.

The pressure of the sealing gas in the discharge hoppers |35 and |35'exists in the conveyor tube 15, the hopper 14, the conveyor tube |38 andthe duct 204, as well as in the feeding hopper 205 which feeds the usedcatalytic material to the catalytic revivifying chamber 203.

The feeding hopper 205 is provided with a cone type valve 206 actuatedby hydraulic operating mechanism 201. A duct 208 connects the feedinghopper 205 with the sealing hopper 209. A rotary bucket type valve 2 I0is operated by motor 2| for passing the catalytic material to bereviviiled into the revivifying chamber 203. The revivied catalyticmaterial is withdrawn from the revivlfying chamber 203 by bucket typevalve 2 I2 operated by an electric motor 2I3, for passage into sealinghopper 2|4. The revivifled catalytic material leaves hopper 2|4 past acone type valve 2 I 5. The cone type valve 2|5 is provided withhydraulic operating mechanism 2 6, The hydraulic operating mechanisms201 and 2|6 are supplied with hydraulic operating fluid through pipes2|1 and 2I8 which are in turn supplied through pipe 2|9 by pump |28. Itwill be observed that the six hydraulic operating mechanisms, that is,mecha.- nisms II5, |I5', |25, |25', 201 and 2|6 are interconnected sothat the revivifying operation and cracking operation are synchrcnizedto continuously supply catalyst and revivify it for reuse whereby thecatalyst particles are continually circulated through the system at anelevated temperature. In other words, the catalyst material iscontinuously passed from the revivifier to the reaction chamber, back tothe reviviiier in a continuous circulating ring, and the hot vapors tobe cracked are continuously passed in contact `with the moving stream ofcatalytic material.

The revivied catalytic material from sealing chamber 2|4 passes the conetype valve 2|5 for 'delivery into discharge hopper 220.

A vibrating screen 22| provided with vibratory actuating means 222screens out the nes 4which pass into a fines collecting hopper 223. Therevivified screened catalytic material passes through duct 224 into ahopper 225 from which it is withdrawn through duct 226 for passage tothe feeding conveyor tube |08, for carriage by conveying means I I tothe lcatalyst distributing bin 6|. Fresh catalytic material to replacethe fines is supplied from hopper 221A through duct 228 controlled byvalve 229, and auxiliary hopper 230 and duct 23|, which is controlled byvalve 232. `It will be noted that the catalytic revivier is underpressure, and the auxiliary hopper 230 acts as a lock. In other words,by operating valve 229, catalytic material is fed from hopper 221 to theauxiliary hopper 230. Valve 229 is then closed and valve 232 is opened,permitting material to pass through duct 23| into the revivifiedcatalytic material discharge hopper 220.

AThe revivication of the catalytic material in the revivier chamber 203is by oxidation of the carbon and adsorbed heavy hydrocarbons. Air istaken from the atmosphere through air intake pipe 232' and is compressedby compressor I8| and delivered through 233 to an air receiver tank 234which supplies air through pipe |49.

In starting the unit, the Valve |5I is openedto supply air to the burner|52, to which fuel gas is supplied through pipe |53, the hot gasespassing through duct I'into the revivifying chamber 203. After thechamber is suiciently heated. valve |5\| is closed and valve |63 isopened to permit air to pass through duct |80 into the revivifyingchamber.

-reaction are withdrawn from the revivifying chamber 203 through a ductlilior passage to a ilue |1| by opening dampers 12 and |18. A blower |10is adapted to withdraw flue gas through duct lllfor deliverythrough`duct |11 into duct |00 to the revivifying-chamber for con-ltrolling the temperature of therevivication reaction." Preferably induct |10 is interposed any type of cooler such as a waste heat boiler toreduce the gases to the desired temperature.

lllue gas is withdrawn from `duct |1I through pipe |02 for compressionby compressor i and delivery to the sealing ilue gas receiver |00. Thesealing nue gas receiver l supplies sealing gas to manifold |32.

' In operating our process, the reaction temperature maintained within-the catalyst bed may vary from 800. F. to 950 F. The catalytticmaterial employed may be any suitable material as, for example, aluminadeposited upon silica gel. The catalyst may pass through the reactionchambers vat a space velocity ofv from two to ten or more barrels perhour of charge per ton of catalyst material in the bed de nding on thedesired pe u described.

crack per pass.

It is found that the gasoline yield will be any- I where from ten totwenty per cent or more greater .run amounted to 17% by weight of thecatalyst, it

was found that a reduction of the carbon by burning in, the revivifyingchamber to 7.2% by weight of the 'catalyst gave a catalytic materialwhich was eietively used and compared favorably with an operation inwhich fresh catalyst wasy continuously charged.

It is believed from the 1foregoing that our method will be' clear tothose skilled in the art. The operation of our apparatus will beunderstood from the foregoing description. It wiilbe seen that we haveaccomplished the objects of our invention. We have provided a method ofcatalytic cracking in which the composition of the oil vapor leaving thecatalyst chamber is substanv tially constant. This enables us to heatthevapors leaving the-first reaction stage and to pass the cracked vaporsleavingthe ilnal reaction stage without special precautions being takenfor a change in its composition. This is not true in- '.the intermittentprocess in which fresh catalyst material beds are operated atprogressively de- A creasing activity due to the continuous decrease inactivity of the catalyst as the reaction prothe period.

In a copending application, Serial No. 199,702. there is shown a methodof supplying` the heat of reaction to individua) reaction chambers bycirculation of a heating medium around the catalyst asvam heat exchangetherewith. There is also shown a simple chamber wherein the heat ofreaction is supplied by the sensible heat of the oii vapors entering. Inthe present disclosure. excessive pre 5 heating of the vapors isavoided'by a series of .chambers with intermediate stages of heating.

Although the apparatus has been described in connection with a processoperated-under pressure conditions slightly above atmospheric, it may aslo well be operated at atmospheric pressure or under' sub-atmospheric orvacuum conditions.

While a catalytic cracking process has been described as particularlyadapted te the apparatus, it is also suited to other endothermiccatalytic re- -actions such as a catalytic reforming of naphtha.

It will be understood that certain features and subcombinations are ofutility and may be employed without reference to other features andsubcombinations. 'I'his is contemplated by and 20 is'within the scope ofour claims. Itis further obvious that various changes may be'made indetails within the scope of our claims without departing from the spiritof our invention. It is, therefore, to be understood that our inventionis not to be limited to the specific details shown and We claim: o

' 1. In an apparatus for the catalytic conversion of hydrocarbon oils, atirst heating means, a ilrst i reaction chamber, means for charging thehydrocarbons to be convertedV to saidilrst heating f means.means'providing communication between said ilrst heating means and saidrst reaction chamber, a second heating means. a second reu actionchamber, means providing communication between said first reactionchamber and said second heating means, means providing communicationbetween said second heating means and said second'reaction chamber,means for continuously feeding comminuted catalytic material te said re`action chambers, means for continuously withdrawing catalytic materialfrom said reaction 4chambers, means for withdrawing reacted hydrocarbonsfrom said second reaction chamber and u means for passing catalyticmaterial withdrawn f m said second reaction chamber into said iirstaction chamber.

2. In an apparatus for the continuous catalytic #conversion ofhydrocarbons by a cyclic procedure w involving-alternately contactingactive particles of catalyst with hydrocarbon vapors to convert them byan endotherrnic reaction followed by contacting the used catalyst withan oxygen-contaming gas to remove deposited carbonaceous material 55" bycombustion, in combination. a plurality of hydrocarbon conversionchambers, means for continuously feeding hot active finely dividedcatailytic material to and for withdrawing used catalyst particles fromsaid'chambers. means for supo@ plying and passing heated hydrocarbonvapors undergoing conversion through .the first of said chambersincontactwith the circulatingmanof active catalyst particles therein,means for heating and passing hydrocarbons partially converted .g5insaidiirstchamberthroughasecondoonveraion chamber in contact with thecirculating ma. of

- active catalyst particles therein, means for oontinuous'lyregenerating by combustion usedcatalystwithdrawnfromthe'tirstconversionchamber ber and means' forcontinually passing partially active catalyst i'rom the second tothefirst cunpassing through the chambers, and in indirect 7g lver-sionchamber wherebythe catalyst particles are continually circulatedthroughout the system at an elevated temperature.

3. In an apparatus for the continuous catalytic conversion ofhydrocarbons by a cyclic procedure involving alternately contactingactive particles of catalyst with hydrocarbon vapors to convert themby'an endothermic reaction followed by contacting the used catalyst withan oxygen-containing gas to remove deposited car-bonaceous material bycombustion, in combination, a plurality of hydrocarbon conversionchambers, means for continuously feeding hot active finely dividedcatalytic material to and for withdrawing used catalyst particles fromsaid chambers, means for supplying and passing heated hydrocarbon vaporsundergoing conversion through one of said chambers in contact with thecirculating mass of active catalyst particles therein, means for heatingand passing hydrocarbons partially converted in said iirst chamberthrough a second of said conversion chambers in contact with thecirculating mass of active catalyst particles therein, a regenerationchamber, means for passing an oxygen-containing gas through saidregeneration chamber, means for continually passing used catalystwithdrawn from both the first and second conversion chambers to saidregeneration chamber, and means for continually withdrawing hotregenerated catalyst from said regeneration chamber and directlyreturning a portion thereof to each of said first and second conversionchambers.

- WILLIAM J. DEGNEN.

HENRY M. NELLY, Ja. PERCIVAL C. KEITH.

